Stoker



S. G. JONES sToKEa March 25, 1,941.

Filed O'Ct. 2, 1939 2 Sheets-Sheet l fw ATTORNEYS.

March 275, 1941. l s, G, JQNES 2,236,407

/ A INVENTOR.

@Mw wwf M 'ATTORNEYS Patented Mar. 2.5, 1941 PATENT OFFICE STOKEE' Samuel G. Jones, Princess Anne County, Va.,f

assigner to Berkley Machine Works and Foundry Company, Inc., Norfolk, Va., a corporation of Virginia Application October 2, 1939, Serial No. 297,427.

Claims.

` 'I'his invention relates to stokers for automatically feeding coal to a fire, and more particularly to means for breaking up the coal into smaller pieces within the stoker.

In locomotive stokers, for example, a trough is mountedon a locomotive tender below an opening in its coal bin for receiving coal therefrom. The vertical front wall of the trough is provided with an opening from which a conduit extends forwardly to the fire box of the locomotive. A conveyor screw is rotatably mounted in the trough and extends intol the conduit for moving the coal out of the trough and through the conduit to the re box. Due to thefact lthat much of the coal may be in pieces too large to pass into the conduit it is customary f practice to mount what is known as a coal crusher-in the trough at the entrance to the conduit. This crusher usually takes the form of a plurality of sharp projections projecting toward the rear end of the trough and arranged in a semi-circle around the upper half of the conveyor screw. Such crushers have several dis advantages. the coal into particles which are so small that a large proportion of them may be carried out Aof' the stack of the locomotive by the draft without burning. Another diiculty is that' the crusher interferes with feeding of the coal because it knocks the pieces around in the trough to such an extent as to cause them to surge violently or boil atA the entrance to the conduit instead of passing into it in an orderlyfmanner. A further disadvantage lies in the fact that the crusher is likely to be torn loose from the trough.

It is among the objects of this invention to provide a stoker crusher of simple and inexpensive construction, which is durable and exceptionally efficient in operation, which does not pulverize the coal, which does not cause the coal to boil around it, and with which `there is no danger of its being forced out of place.

In accordance with this invention the crusher has a body portion provided at one end with an opening for receiving the conveyor screw and. extending rearwardly and outwardly over thescrew. The inside of the crusher is provided with one or more arcuate shoulders encircling the upper portion of the screw and preferably disposed in planes inclined to the axis of the screw to give the eect of a screw thread as the coal is forced into the crusher by the conveyor screw. The thread of the conveyor screw preferably increases in diameter from the rear end of the crusher toward its front end so as to produce a One is that they crush or grind shearing action in cooperation with the arcuate edges of the crushers shoulders. To securely hold the crusher in place the tubular conduit that extends forward from the opening in the front wall of the trough has an extension projecting back into the trough a short distance. This extension is provided with one or more shoulders that are engaged by cooperating projections on the crusher in order to relieve the bolts that connect .the crusher to the front wall of the trough from thetorsional strain exerted by the crusher.

'Ihe preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is afragmentary plan view of a locomotivestoker showing its trough with my crusher mounted therein; Fig. 2 is a. side view thereof partly broken away to show the crusher in vertical section; Fig. 3 is anlenlarged vertical section of trough and crusher taken on the line III-III of Fig. 1; Fig. 4 is a view looking forward into the crusher; and Fig. 5 .is a Vbottom view of the crusher.

Referring to Figs. 1 and 2 of the drawings, a locomotive stoker conveyor trough l is adapted to be mounted on a locomotiveV tender (notl shown) in the usual way below its -coal bin in order to receive coal therefrom. The trough carries a pair of wheels or .rollers 2 that are guided on tracks on the tender inl order to permit the trough to move relative to the tender to compensate for the relative movement between tender and locomotive. The front wall 3 of the trough is provided with an opening 4 from which a sleeve 6 projects forward for removably receiving the rear end portion of a tubular conduit 1 that extends forward to the locomotive. To detachably connect the tubular member to the susV trough so that either can be readily removed and replaced when worn, the' front end of the sleeve is provided with a peripheral flange 8 to which a similar flange 9 on the tube is bolted.

Coal is fed forward along the trough and through tubular conduit 1 by means of a conveyor screw Il rotated by a smalll steam engine (not shown) rpreferably mounted on the locomotive. The engine is connected to the rear end of the screw through suitable telescopically and universally connected shafts I2 (Fig. 2) that drive a speedreducing gear unitl3 mounted inback of the .trough where it is operably connected to the rear end of the screw.

It is a feature of this invention that large pieces of coal in the trough are broken into smaller piecesso that the conveyor screw can carry them forward into the tubular conduit. This is done by relatively large pieces.

means of a crusher which does not pulverize the coal and which does not cause it to boil in the trough at the entrance to the conduit. Accordingly, the crusher I6 is a roughly semi-circular casting that overlies the upper portion of the screw. The front end of the crusher is connected to the front wall of the trough in a manner about to be described, and the crusher extends rearwardly and ares outwardly away from the screw similar to a funnel. In order to crush coal eiectively without requiring a great deal of power the inner surface of the crusher is provided with a plurality of concentric shoulders Il partially encircling the screw. Each shoulder has an arcuate lower surface and a substantially vertical lateral surface meeting the lower surface at substantially a right angle to form an arcuate cutting edge for the coal. As' the coal is forced against these shoulders by the conveyor screw, it is broken into pieces small enough to pass into the conduit. As shown in Figs. 1 and 5, the shoulders are preferably disposed in planes inclined to the axis of the screw to produce a thread effect that guides the coal into and through the crusher as the coal is moved ahead by the screw. Due to this and the lack of projecting ngers, the coal does not boil around in the trough and crusher and become pulverized, but passes directly through the crusher in an orderly manner in Once a piece of coal enters the crusher there is nothing to knock it back outagain.

Another feature of this invention is that the screw thread increases in diameter from the rear end of the crusher toward its front end, as shown in Figs. 1 and 2, so that it exerts a shearing action on coal between the periphery of the thread and the edges of the shouders. The result is that less power is required for the coal crushing operation.

A still further feature resides in the manner in which the crusher is fastened in place in the trough. The rear end ofl tubular conduit 1 projects into the trough ay sort distance and its lower half is cut away to form a pair of downwardly facing shoulders 2|, as shown in Figs. 2 and 3. The front portion of the crusher rests on this tubular extension and has inwardly projecting lower portionsforming shoulders 22 that extend under and engage the tube shoulders for preventing the crusherfrom being rotated or moved in the transverse plane of the tube.

To hold the crusher on the tube extension it is provided at opposite sides with lugs 23 from which bolts 24 extend through the front wall of the trough. With this construction the bolts merely hold the crusher on the tube, and the tube itself takes the torsional strains exerted by the crusher which might votherwise shear off the bolts. 'I'here is thus no danger of the crusher being torn loose from its mounting.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention and have I illustrated and described what I- now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In a stoker, a trough provided at its front end with an opening for receiving a conveyor screw, a tube extending forward from said opening and having an extension projecting into the trough provided with a shoulder, a crusher overlying at least the upper portion of said extension and provided with ashoulder engaging said tube shoulder to lock the crusher against movement transversely of the tube, and means for holding the crusher against movement axially of the tube.

2. In a stoker, a trough provided at its front end with an opening for receiving a conveyor screw, a tube extending forward from said opening and having an extension projecting into the trough, the lower portion of said extension being cut away to provide shoulders, a crusher mounted on said extension and provided with inwardly projecting portions engaging said shoulders to lock the crusher against movement in the transverse plane of said tube, and means for locking the crusher against movement axially of the tube.

3. In a stoker, a trough having a front wall provided with an opening therethrough for receiving a conveyor screw, a tube extending forward from said opening and having an extension projecting into the trough, the lower portion of said extension being cut away to provide shoulders substantially perpendicular to said front wall, a crusher mounted on said extension and having inwardly projecting lower edges engaging said shoulders for locking the crusher against movement transversely of said tube, and means for fastening the crusher to said front wall to prevent it from moving axially of the tube.

4. In a stoker. a trough having a front wall provided with an opening therethrough for receiving a conveyor screw, a tube extending forward from said opening and having an extension projecting into the trough, the lower portion of said extension being cut away to provide shoulders substantially perpendicular to said front wall, a crusher mounted on said extension and extending rearwardly over the screw and flaring outwardly therefrom, the inside of the crusher being provided with an arcuate shoulder extending transversely of the trough, the lower edges of the crusher projecting inwardly and engaging said tube shoulders for locking the crusher against movement transversely of said tube, and means for fastening the 4crusher to said front wall to prevent it from moving axially of the tube. y

5. In a stoker, a troughI provided at' its front end with an opening for receiving a conveyor screw, a tube extending forward from said opening and having an extension projecting into the trough provided with a substantially horizontal shoulder, a crusher engaging at least the upper portion of said extension and provided with a substantially horizontal shoulder engaging said tube shoulder to lock the crusher against movement transversely of the tube, and

means holding the crusher against movement' axially of the tube.

- SAMUEL G. JONES. 

